1. Field of the Invention
This invention relates to multi-channel sensing, especially to a multi-channel sensing system and an operating method thereof applied in a touch display panel.
2. Description of the Related Art
With the development of display technology, display panels with touch function have been widely used in all kinds of electronic products such as television, plat display, mobile phone, tablet PC, or projector and they are popular in the market.
In general, a conventional liquid crystal display with mutual capacitive touch function includes a display panel, an ITO sensor, and a touch control chip. The ITO sensor includes a plurality of sensing lines and a plurality of driving lines. The touch control chip includes a plurality of pins. The sensing lines are coupled to the pins respectively. After the driving line transmits a driving pulse and a small voltage is coupled at the sensing lines, the touch control chip will sense the coupled voltage and determine whether the ITO sensor is touched according to the value of the coupled voltage.
However, with the increasing size of the display panel, the conventional liquid crystal display has some drawbacks such as long touch reaction time, low scan rate, and the noise generated by the display panel will seriously affect the operation of the touch control chip and even cause error in touch point judgment. In some systems, an insulating material is disposed between the ITO sensor and the display panel to block the noise generated by the display panel; however, this structure will increase cost and the thickness of entire apparatus will be increased and this is not conducive to mechanical design. In addition, since the conventional touch sensing apparatus also needs amplifier to amplify the coupled voltage, it is hard to decrease the die size and the cost cannot be further decreased.
Therefore, the invention provides a multi-channel sensing system and an operating method thereof applied in a touch display panel to solve the above-mentioned problems.